Project Summary - Photodynamic Therapy to Prevent Arterio-Venous Fistula Maturation Failure: An Unmet Clinical Need Establishing and maintaining arteriovenous (AV) access sites is critical for patients on hemodialysis. The most preferred AV access is the forearm fistula which is now used for the majority of hemodialysis patients. However, a common problem with AV fistulas is primary maturation failure, i.e. following surgical placement, their fistulas do not become viable for dialysis without additional percutaneous or surgical interventions and some never become viable. This failure can lead to increased morbidity from prolonged use of central venous catheters and results in a large financial cost to the health care system. This is particularly frustrating because it is well established that a mature fistula provides the hemodialysis patient with the most effective means of AV access. While the exact mechanisms of maturation failure are not fully understood, it is generally accepted that post-surgical neointimal hyperplasia and inadequate venous remodeling play key roles and preventing either of these processes should substantially improve AV fistula outcomes. This project will investigate the potential for a particular form of photodynamic therapy to improve fistula maturation rates. Preliminary studies in related cardiovascular models indicate this therapy could substantially impact the main failure mechanisms involved in fistula maturation failure. From a commercialization perspective, this therapy also has the advantage that is already under late stage development in an unrelated disease indication, thus the typical drug development risks are substantially reduced. The project will be a joint effort between a commercial entity whose staff has extensive experience in vascular photodynamic therapy and a research partner who is a leader in AV access preclinical and clinical research. This Phase I project will focus on validating this therapy in an established preclinical model of AV fistula maturation failure. If this project is successful, it is envisioned that this technology should be suitable for initial clinical feasibility studies within the near term.